Maximum Likelihood Sequence Detection for GMSK

This zip file contains a regular and fast versions of the so called "Maximum Likelihood Sequence Detection" for GMSK.

This zip file contains a regular and fast versions of the so called "Maximum Likelihood Sequence Detection" for GMSK. It employs the Viterbi Algorithm to solve the MLSD problem. Trellis of GMSK is reduced state as written in necessary paper and thesis' I have used as reference. There are both coherent and non-coherent receivers. In fact coherent / non-coherent receiver uses the same structure but a "forgetting factor" method is employed in order to create the difference. Mathematical background as well as references can be found in the project website.

There are two test files. "GMSK_MLSD_test.m" script is more straight forward and easy to understand, it employs only for loops to solve the Viterbi Algorithm. "GMSK_MLSD_fast_test.m" employs some convolution tricks to decrease the computation time, it is around 2 times faster compared to the regular script.

This is essentially a soft input hard output type Viterbi Algorithm, so with some modifications it can be easily employed to any type of solver that uses Viterbi Algorithm.